Cleaning Rimmed Cartridge Case Head Groove.

[kenhwind]

I have been putting off posting this question because I am inclined to think that some form of wet/sonic cleaning process is the answer.

So, does anyone have a convenient method to clean out the narrow case head groove on rimmed, mostly handgun, brass.

Gun oil, powder residue, case lube and probably some tarnish from handling while shooting. The polishing disc by hand works okay but is time consuming. I use a Lyman vibrating tumbler, I might need to upgrade to something better.

 

[DShortt]

A wet tumbler and SS pins will remove that, but that might not be an option you're comfortable with.
Dry media is more or less a ball, and won't get into small, sharp crevices like that.

 

[Straightshooter1]

Definitely this ^^^^^

 

[mongo chicago]

Hoppe's. has brass pics that may help

 

[Charliemac]

Try a brass wire brush?

 

[ricco1949]

A good sonic cleaning or wet tumbling with pins should remove it.

A trip through your dish washer in a separator may even do the trick.

 

[gdbleb]

Have you tried walnut media? That is smaller than corncob and a bit more aggressive. It's dusty though (at least mine is) so use a dryer sheet. And you'll need a trip through the corncob to clean off the dust.

 

[powderbrake]

I have done tens of thousands of rounds of 38 special, 357, 44 Mag and 44 special and 45 Colt over the past 60 years, and have not experienced a problem with stuff in the corner. I use a Midway vibrating tumbler and a 5 gallon rotating drum that I built.
I use a medium grind of corn cob, with a little bit of Dillon rapid polish. Maybe you have a larger grind, or your medium may be dirty. Will a fresh batch of corn cob with no polish compound get it clean ? (clean out the inside of your tumbler first) If so, change your corn cob more often.

 

[ricco1949]

I have done tens of thousands of rounds of 38 special, 357, 44 Mag and 44 special and 45 Colt over the past 60 years, and have not experienced a problem with stuff in the corner. I use a Midway vibrating tumbler and a 5 gallon rotating drum that I built.
I use a medium grind of corn cob, with a little bit of Dillon rapid polish. Maybe you have a larger grind, or your medium may be dirty. Will a fresh batch of corn cob with no polish compound get it clean ? (clean out the inside of your tumbler first) If so, change your corn cob more often.

Do you have a photo of your 5 gal rotating drum set up?

How many brass will it handle?

 

[DShortt]

Could be this was particularly dirty brass or it's accumulated over a significant period of time?

Just guessing.

 

[kenhwind]

Have you tried walnut media? That is smaller than corncob and a bit more aggressive. It's dusty though (at least mine is) so use a dryer sheet. And you'll need a trip through the corncob to clean off the dust.

I didn't think of that, and I actually have some.

 

[Clancy]

Square patch draped over a dulled razor blade.

I do it all the time. Just be sure you dull the blade.

 

[kenhwind]

I tried a wire brush on a Dremel, but it will not get into the groove, The brass cleaning brushes are almost useless.
I just looked at some of my cases and this isn't an issue with all of them, so maybe I need to tumble longer or change the media more often. I have been using the Lyman "Treated" corncob media for years but have some of the older Tuffnut that I'm going to try.

Any recommendations for how often to change the media?

 

[powderbrake]

Her are some pics of the 5 Gal tumbler per request by Rico1949.






Probably best to look at pic #4. The motor drives the two connected together pulleys which rotate freely on a sleeve bearing on the closest 3/4 inch shaft. The belt then drives the rear shaft. There are two larger diameter rubber covered sections that drive the 5 Gal Drum. The closest shaft has a couple of small pulleys with rubber tubing tires to support the drum. The closest shaft simply idles in a set of bearings.
Note there is a vertical bar with a roller on it to contact the top of the drum to keep it in place as it rotates
The drum rotates at 48 rpm.

The drum is a 5 gallon can which I lined with sheet rubber about I/8 thick. Also glued rubber to the top of the can. This is the keep the noise down.

I could put 1000 38 specials in the can. I was shooting a lot of bullseye in those days mostly with S&W Model 52 and S&W Model 28. I usually ran about 400 or 500 pcs when I was re;loading.

Click on pics for an expanded view.